Regulating device



Nov. l2, 1957 F. c. REGGIO 2,812,746

REGULATING DEVICE original Filed Nov. 1s, 1942 :s sheets-sheet 1 Nov. 12,1957 F. c. REGGIO 2,812,746

REGULATING DEVICE Original Filed Nov. 18, 1942 3 Sheets-Sheet 2 /09 /n u r f l INVENTOR.

Nov. l2, 1957 F. c. REGGIO .REGULATING DEVICE Original Filed Nov. 18, 1942 INVENTOR sims e 'REGULATING DEVICE e Ferdinando Carlo Reggio, Norwalk, Conn.

Continuation of abandoned application Serial No. 466,041, VNovember 18, 1942. This application January 6, 1954, Serial No. 402,452 i 9 ciaims. (ci. 121-42) This invention relates to regulating systems such as speed governors or similar control apparatus provided with stabilizing or anticipatory means `to prevent hunting, provide automatic compensation for certainvariables or regulate the rate of response of the system to changes in the controlling operating conditions. The instant application is a continuation of my application Serial No. 466,041, tiled November 18, 1942, now abandoned.

One-of the objects is to provide a speed regulating system which is comparatively simple and compact,` requires a small number of moving parts and is relatively inex- 'United States Patent-O 2,812,746 Patented Nov. l2, 1957 The illustrative embodiment shown in Figure 1 includes l hydraulic governor 6 having a servo piston 8 for conftrolling the supply of actuatingsubstance to a prime mounted in a bore 22 formed in the governor body 15 coaxial with the cylindrical extension 14. A`V Speeder V:spring 23 applies axial downward load to the pilot valve 21 directed against the centrifugal load transmitted there- Vto by the yballs 18. An axially adjustable member 24 one or more operative conditions alecting the speed to be regulated. e. y

Still another objectresides in the provision of anticipatory and stabilizing means in connection with regulating devices for preventing irregular operation thereof such as hunting or throbbing.4 f 1 i A further object of the invention is to provide improved hydro-electrical control systems which are capable of decreasing the time lag between the input 2 signaland the initiation of the output response, and of controlling the speed rate of suchresponse. t

Another object is a regulating system which provides engine speed regulation to compensate for speed variations due either to load changes or to throttle position changes and does so accurately and efliciently and without hunting.

A further object is to provide an improved control system for a powerplant-generator and interconnected power system for maintaining system stability throughout variations in the power demand of the connected load.

A further object is to provide a device of the `typedescribed capable of limiting the ,rate of change of the condition being controlled to a predetermined value,` regardless of the rate of change of the input signal.

Other objects and advantages of the invention will become apparent from the following description takenin connection with the accompanying drawings, in` which:

Figure 1 is a section through a speed regulating system for the control of a prime mover connected with an electric generator. ing a partial modicationof the` governor of Figure 1.

`Figure 3 is a section throughan aircraft engine speed regulating system, Figure4is a section through a speed regulating system particularly intended fora,vehicle, and Figure 5` is a sectionalongthe line 5e-5 of Figure 4.-..

connected by way of a ball bearing with the spring 23 serves to control the load of the latter and in turn the speed of the prime mover. Agovernor cover 25, only partially shown, may be providedA for enclosing the ilyball `mechanism and guiding the slidable member 24. `Inop'eration the pilot valve 21 isdriven in rotation by the flyballs 18 owing to the friction therebetween. i i

The pilot valve 21 has lands 26, 28 slidably fitting the A:bore 22 andfunctioning as plugs to cover and uncover the lateral ports 30 and 31`respectively. Between lands 26 and28 the pilot valve has a portion of reduced diameter, and the open stace so afforded communicates witha lateral passage`32 at all times. The pilotvalveiisshown inneutral position, in which both setsrof ports 30 and 31 are closed. An oil reservoir 33 is provided in the' governor body 15 and communicates with the ilyball compartment, with ports 30 and with the, suction sideof a gear pump 34 which may be driven from the governor shaft 11. The discharge side of this `pump is connected with the ports 31 and with a pressure oil accumulator comprising a spring-loaded valve plunger 35 slidable in a `borei36 and controlling a by-pass` for leading oil back to the reservoir `secured to the latter is adapted for` connetcion with the control device ofthe prime mover for regulating the l supply lof energythereto Displacement of rod 40 toward the left or the right will respectively increaseo'r decrease said supply and` cause an increase or decrease of speed.

The cylinder chamber 41 on the left side of piston 8 is closed by a cover 42a'nd contains a compression spring 43 operating on the piston 8 in opposition to the oil pres- ;sure in chamber 38. A submerged small orice 44whose effective area may be adjusted by means of a needle1 valve `45 connects the oil reservoir 3 with the cylinder chamber- 41, and a duct 46 connectsthe latter with a chamber48 provided at the lower end of the bore 22.

A housing 50 is attached to the governor body 15, with a plate 51 interposed therebetween, and includes a flexible 1 diaphragm or bellows 52" defining a chamber 53 which ,cornmunicates` with`chamber 48" by way of a passage `formed in plate 51. ConicalV compression."springs 54, 55

are mounted within the housing `5l), the former between plate`51 and the bellows," and the latter between the bel- :lo'ws and an adjustable seat 56 having a threaded connec- `tion with the housing 50 and provided witha lock nut L58. The rate of `deflection of bellows 52` may be `varied by changing the axial adjustment of the seat 56. When the latter is in its lowermost position a large number fof coils of the springs 54and 55 are active, and the rate of ldeection'of the bellows has its maximum designed value.

lf the seat 561is raised-both springs are compressed, and

`an increasingnumber of the. larger coils thereof-come t intocontac't with their seats andbecome inelfective, `leavand slidably mounted in a bore provided in the seat 56 is connected at its lower end with a solenoid deviceindi- `-ca'ted generally at 59 and including an armature 61 slidably supported by lguides 62, 63 and coacting with a solenoid coil 64 connected with a shunt 65 interposed in -one ofthe supply lines of the network 10, the Vvoltage across the shunt, proportional to the generator load, being impressed on the solenoid. An adjustable rheostat 66 and a switch 68jare connected in series with the solenoid. While fthisexample of solenoid arrangement is intended for a direct current system, the modifications thereof for application to an alternating current system will be kobviousito those skilled in the art.

Assuming 'that the switch 68 is open, and therefore that the solenoid 59 is inoperative, as the prime mover runs at steady speed the flyballs 18 maintain the pilot valve 21 rcenteredin neutral position as shown in the drawing. The oil in chambers 41, 48 and 53 has the same pressure as in the reservoir 33 with which these chambers communi- ',cate 'through the orifice 44. Neglecting the weight vof the pilot valve 21,V the centrifugal force and the resilient Vload applied thereto by the fiyballs 18 and the spring 23 respectively are in equilibrium. If the load on the prime Ymoverdecreases7 the speed increases, and the augmented centrifugal for'ce lifts the pilot valve thus opening the ports 30, causing discharge of oil from chamber 38 to the reservoir 33 and displacement of the servomotor piston 8 vtoward`the`right under the load of the compression spring v43. This movement of the servomotor decreases the supply of actuating substance to the prime mover and causes 'the speed'thereof to decrease.

This `speed-decreasing movement of the servomotor would eventually be checked as the pilot valve resumes its "neutral position and closes the ports v30, but by this vtime 'the prime mover is decelerating and its speedrwould r"continue to drop below normal, whereupon the diminished "centrifugal forceV causes downward movement of the ypilot valve, the ports 31 are opened and the vservomotor piston Nrnoves'to the left so as to increase the prime moversupply of actuating substance and the speed thereof.

The -l'atter however attains a value higher than the normal speed, and the irregular cyclical speed variation generally 'referred to as hunting is likely Vto rcontinue Vin- `definitely. Tol correct this condition of instability various compensating or stabilizing arrangements have been proposed. 'Ac'cording to the invention a variable compensating uid'pressure load is applied to one endof the-pilot valve, in a manner to be later described.

Upon a decrease of load on the generator, consequent acceleration of the prime mover and upward displacement of the pilot valve, the servomotor piston S begins `to move toward the right and oil is'sucked from bellows chamber 53 causing contraction of the bellows 52 from its position of resilient equilibrium. Only a small amount of oil flows into chamber 41 from the reservoir 33 through the orifice 44. As a result the oil pressure in `chamber 48 temporarily drops below the value of the pressure which surrounds the upper end of the pilot valve 21, and a transient downwardly directed differential pressure load is thus applied to the latter,and restrains the ,upward displacement thereof.

Although this transient restraining action exerted on the pilot valve is very small as compared to the centrifugal force transmitted thereto v by the flyballs and by the spring 23, it causes the pilot valve to return suiciently quickly to its neutralrposition, so that an underspeed condition of the prime mover does not occur. As the prime mover upon the correcting action of the servomotor gradually returns Vto normal speed, oil from the reservoir 33 iiows through orifice 44 Vinto chambers 41, 48 and 53, thus progressivelyreturn- `of the governor and reduce the magnitude of the speed n surges occurring-under `suddenvariationsof load. Owing tothe Ileakage valve-445the action of the-solenoid device t 59 onthe pilotvalve 21 isof a'temporary nature. The

asi-2pac ing the bellows 52 to its original position of equilibrium and relieving the suction force exerted on the lower end of the pilot valve. The leakage through the orifice 44 is regulated by means of the needle valve 45 in such a manner that the speed of the prime mover returns to normal at the same time .that the oil pressure in chamber 48 resumes the same value as in the oil reservoir 33. Furthermore the .rate of deflection of bellows 52 may be adjusted by varying the axial position of the lower spring seat 56.

When the load on the prime mover is increased its speed decreases and the action of the governor is the reverse of that just described. The pilot valve is then pressed down by the spring 23 acting against the decreased centrifugal force. This opens the ports 31 to admit pressure oil to the cylinder chamber 38 causing displacement of the servomotor piston 8 to the left and thereby increasing the prime mover supply of actuating substance.l Most `of the oil displaced by piston 8 from chamber 41 flows to the bellows chamber 53 resiliently expanding the latter, thereby causing increaseof oil pressure in chamber 48 -so as to exert a transient upward pressure load tothe Vtransient restraining action exerted upon the pilot valve 21 and tending to return the same to neutral position is proportional to the square of the speed of motion of -the servo piston 8 and therefore is effective tornaintain ythe rate of motion lo'f said piston, yhence the rate of variation of the condition controlled thereby, within desired limits even for high rate of change of the input signal -applied to thepilot valve. Theforegoing restraining actionwill be more fully set forth in connection with Figure 2. Y, Y

Theabo've manner of operation 'is obtained when the switch 68 is open, with the solenoid coil 64 not energized 'and the armature 61 inoperative. However, vwhen the Vswitch 68is closed the solenoid is energized and a downwardly directed electromagnetic load proportional to the generator load is applied to the armature 61 and is transmitted'bymeans of the rod'60 to the bellows 52. lf the .load on the generator supplying the network 10 increases suddenly, the current energizing'the solenoid 64 increases laccordingly causing a sudden increase ofthe downward pull that the armature 61 exerts on the bellows 52. The latter will tend Vto expand, causing suction in chamber 48 and determining a downward movement of the pilot valve so as to uncover the ports 31 andinitiate a movement of the servomotor piston 8 in a direction to increase the supply of actuating substance to the prime mover even before the ,yballs 18 have .detected Ya drop of speed. The V'reverse action occurs upona sudden decrease in electric load in thenetwork 10`which determines-a decrease of-the'down ward pulltransmi'tted by the "armature 61 tothe bellows 5.2. Thelatter tends to move upward, increasing the oil pressure in chamber 48 and determining an upward displacement of thepilot valve 21 so as'to open ports 30 and initiate an excursion of the servomotor piston 8 in a `speed-decreasing .direction in anticipation Vof the prime mover acceleration which would otherwise follow the reduction -of load.

It willbenoted that the solenoid device 59 actuates the -pilot valve in the same manner as and ahead of the time at which the latter would otherwise be actuated by the .iiyvballs,\so as to compensate for the delay in the response amounti'of compensation effected by' the solenoid may be `the cushioning effect thereof is quite limited.

adjusted by means of the rheostat66, and by means of rthe seat 56 which serves to regulate the rate of deflection ofthe bellows 52. t v

It will be appreciated that the oil displacement in chamber 41 due to movement of the servomotor piston 8 is many times larger than the oil displacement in chamber 48 caused by sliding motion of the pilot valve 21. For 'the purpose of rendering a numerical example more simple it may be assumed that the seat 56 is adjusted in its uppermost position so as to block the diaphragm 52. In which case as the pilot valve 21 or the piston 8 are moving at a given velocity, the corresponding velocity of the oil` forced through the orifice 44 is proportional to` the square ofthe effective diameter of said valve or piston, and the change of pressure in chamber 48 is proportional to the fourth power of said diameter. Assuming for instance that the face of the piston 8 defining chamber 41 has an effective diameter four times as llarge as that of the pilot valve, when the piston 8 is moving at a certain velocity it determines a transient relative pressure in chamber 48 which is 256 times as large as that occurring when the pilot valve 21 is moving at the same velocity. It will therefore be readily understood that where `the diameter and stroke of piston 8 are so designed in relation to the pilot valve 21, the orifice 44, suitably adjusted by means of the needle valve 45 for correct operation of the governor, will not oppose any appreciable resistance to the free motion of the pilot valve, The danger that chamber 48 may operate as an objectionable dashpot for the pilot valve and prevent rapid displacement of the latter in response to rapid speed changes, thus resulting in serious overspeed or underspeed upon sudden load variations maytherefore be entirely avoided.

Where no anticipatory actuation of the pilot valve by means of the electromagnetic device 59 is desired, the solenoid 59 and the rod 60 may be omitted.` Furthermore in substitution for the resiliently` yloaded bellows52 other equivalent cushioning means may be provided, such as a resiliently loaded slidable piston, or an air accumulator communicating with chamber 48. s

Figure 2 shows a partial modification of Figure 1 indicating an air chamber or accumulator 70 provided in the lower portion of the pilot valve in substitution for the bellows chamber 53, the governor being otherwise similar to that of Figure l. It will be appreciated that this form of governor is extremely simple, compact and contains a very small number of moving parts as compared to other isochronous governors. It will be noted that in the arrangement shown in Figure 2 the air chamber 70,`formed within the lower end of the pilot valve, is very small and If we assume that this form of governor is used to control a variable-speed powerplant, that the latter is operating at low governed speed, and that the operator suddenly moves the control lever to full-speed setting, then the load of the governor spring 23 will be instantly increased to its maximum designed load corresponding to maximum speed of the Powerplant, and as a result the pilot valve 28 will be shifted all the way downward, fully opening the port admitting hydraulic fluid from the high pressure system 31, 36 to the cylinder chamber 38. This motion of the pilot valve will not cause any objectionable pressure `rise in the hydraulic fluid at the lower end thereof, las the small volume of fluid vdisplaced by the pilot valve is in part discharged at low velocity through the orifice 44, while the remainder causes a slight compression of `the air in the cushion chamber '/ti. However, the ensuing `motion of the piston 8 toward the left displaces fluid at a much higher rate, causing a substantial increase in pressure. The air in the cushion chamber 7il soon contracts to a very small volume, whereupon substantially all of the fluid displaced `by the powerpiston 8 must be discharged through the small orifice 44. The resulting increase in fluid pressure exerts on the lower end of the pilot valve 21 a restraining action tending' to `return the same Vto, its neutral position,jwhich actionisV proportional to the square of the speed of mtion of the servo piston 8, and is therefore eective to limit the rate, of motion thereof. It will be appreciated that by `suitably adjusting the effective area of the orifice 44 the maximum rate of motion of theservomo'tor, and in turn the maximum rate of change in the condition being controlled, maybe limited to any desired or predetermined value, `said rate varying in relation to the magnitude and suddennessofV the input signal or load exerted upon the pilot valve. i j i In `the above disclosed arrangement the. governoris adapted to increaseV or` decrease the supply of energy to a prime mover in response to deceleration or accelera- Ation ofthe latter due to increase or decrease of the load applied thereto, respectively.` A different arrangement is shown in Figure `3y wherein a governor 6' operates to increase or decrease the load applied to a powerplant in response to deceleration or `acceleration of the latter respectively, independently of the supply of energy thereto. A hydraulic governor indicated generally at 6' is driven by means of a shaft 11 and gears 72, 73 from an aircraft engine 75 indicated diagrammatically in reduced scale and connectedwith` a variable pitch propeller having blades 76 automatically controlled by the governor 6 so `that theirpitch is automatically modified in accordance with variations in the speedof the engine. To this end each b1ade76 is rotatable about a spider arm attached to the propeller shaft 78.` The latterhas an internal `chamber 80 `and is furnished with a cylindrical cap 81 propeller is in operation centrifugal and aerodynamic forces `tend to turn the blades 76 into coarse or maximum pitch `against said hydraulic pressure.

`The governor 6 may be `similar to that disclosed in connection with Figure 1 except that it does not include the bellows chamber 53 nor the solenoid device 59. Furthermore the `hydraulic servomotor member or cap 81 is `substitute for the servomotor` piston 8 of Figure 1.

` Under steady flying conditions the-pilot valve 21 is in` neutral position. If the engine "speed increases, as may be due to a dive or to increased manifold pressure, the pilot valve is lifted bythe flyballs so as to open the ports $0, pressureoil flows from the propeller chamber 80 through ducts 82, 83 to the reservoir 33, the cap 81 moves to the `right causing the propeller pitch to be increased, and the augmented propeller torque slows the engine `down to normal speed. Conversely, when the engine speed decreased, as may be due to a climb or to decreased engine manifold pressure, the pilot valve drops and opens the ports 31 to admit pressure oil to the servomotor chamber 80, `whereupon the cap 81 moves outwardly and decreases the propeller pitch and the propeller torque until the engine resumes normal speed. It has been found that owing to the considerable inertia of the propeller and to the character of the resistance of the air to the rotation thereof, hunting can be avoided` without resorting to compensation devices in the governor., It is therefore unnecessary `to provide means for applying a `variable operative fluid pressure load at one end of the pilot valve, and hydraulic governors adapter for the control of constant speed propellers and not including any compensating means are well known in the art. According to the invention, however,a variable pressure oil chamber 48 is provided at the lower end of th'e pilot valve 21 and `communicates by means of a leak valve 44' adjustable by way of needle valve 45 with the reservoir 33, and by means of conduits and91 with the cylinders Y86 and88. A piston 92 slidable` in cylinder 86 `is con- Lnected by a rod 93 with a-liexible diaphragm 9,4 mounted A pressure tube anemometer or Pitot tube 104 includes an open -ended inner'tube 105 facing the air stream for measuringf'the total pressure head, and a concentric outer Atube 106 having lateral orifices 107 so arranged 'as to measure the static pressure. The former and latter tubes are connected with chambers 100 and 98 respectively. `If the aircraft air speed suddenly increases as it occurs when a 'dive is initiated the total pressure head in cham- 'ber 100'increases, causing displacement of piston 92 tolward the left Vso as to temporarily increase the oil presl"sure'in chamber48; The pilotvalve is lifted and the propeller cup lslides toward the right so as to increase AthepropellerV pitch in "advance of the time at which the Vpilot 'valve `would otherwise have been lifted upon an `increase lof th'e'ce'ntrifugal force transmitted thereto by 'theflyballs This advance actuation of the pilot valve by means of the anemometer considerably reduces the engine speed surge that would otherwise occur. Conversely, when the aircraft 'air speed suddenly decreases, as when a climb is initiated, the total pressure head in chamber 100 decreases, moving the vpiston 92 toward `the right, creating'suction in chamber 48 and causing 'the pilot'valve to drop so as to initiate an outward move- Yment of the cup 81 to'decrease the propeller pitch ahead 'of the drop of engine speed which would occur with a conventional governor. The lower cylinder 88 is provided with a piston 109 connected by a rod with a flexible resiliently loaded diaphragm 110 separating chambers 111 and 112. The former is vented tothe atmosphere, and the latter is connected by a pipe 114 with the vengine manifold 113. A sudden increase of the engine "manifold pressuredetermines a displacement of the dia- "phragm 110 and piston 109 toward the left and transiently increases the 'oil pressure in chamber 48 so as to lift the pilot valve 21 and increase the propeller pitch in anticipation of the increase of engine torque. The Aactuation'of the ypilot valve 21 by means of the diaphragms 110 and 94 has a temporary character owing to -the action of the leak valve 444.

A still further form of'governor, indicated generally at 120, is shown in Figures 4 and 5, wherein a differential oil pressure varying vwith the speed of the prime mover is employed instead ofthe centrifugal force for actuating vthe pilot valve in response to speed variations. The governor120 includes-a housing 121 comprising a gear pump having an idler/ gear 122 meshing witha ldriving gear 123 which is lkeyed to -a shaft 124 supported in bearings formed in t-he pump housing 121 and in the governor body 125. The `shaft 124 carries a gear 126 adapted to be driven from 'the prime mover. A bore 128 coaxial with shaft 124 is formed inthe governor body 125, and lateral ports 130, 131 and 132 are connected with said bore. A pilot valve 133 slidably and rotatably mounted ^in said vbore is formed with an intermediate portion of reduced diameter, thus providing an annular open space communicating with ports 131 at all times. The terminallportions of the pilot valve control the ports 130 `and 132. When the pilot valve is in neutral position as shown in the drawing the ports 130 and 132 are closed. The ports k132 are connected with a reservoir 134 containing oil atatmospheric pressure, while the ports 130 are-connected with an oil accumulator 135 wherein the pressure/is kept Ysubstantially constant by means of a slidableV resi'liently loaded piston 136 controlling suitable ports.

The passage .131 leads pressure oil to and from the cylinder chamber 138 foractuating the differential servomotor piston 140, thearrangement being such that a'displacement ofthe latter toward the right tends to increase the speed vof the prime mover. The cylinder cha-mber 14'1 atthe opposite sidepofl the piston may contain a Ycompression spring A142-for resiliently loading the latter, andcommunicates withan air chamber V143 and, by way tof duct fi-tawitha chamber -145 at the left Vside of the pilot valve l133. An orifice 146 adjustable by a needle -'valve 148 is provided between said chamber 145 and a chamber 150 which communicates with the discharge side of the oil pump 123. A duct 151 connects the chamber 152 at the right end of the pilot valve with the oil accumulator 135. The pressure chamber 150 communicates with the oil accumulator by way of an orifice 153 adjustable by means of a resiliently loaded needle valve 154 actuated through a cam 156 by a speed control lever 155. A coil spring 158 has its terminal coils securely attached to the shaft 124 and to the pilot valve 133 so as to drive the latter along in rotation with the former.

The pump 123 discharges a quantity of oil proportional to the speed of the prime mover through the orifice 153 thus determining on opposite sides of the latter a difference of pressure proportional to the square of said speed; this oil liows to the accumulato-r 135 and thence through ports 160 returns to the reservoir 134 connected with the suction port of the pump. As the upstream and downstream sides of the orifice 153 are in communication with chambers 145 and 152 respectively, an axial oil pressure differential load proportional to the square of the speed and directed toward the right is applied to the pilot valve 133. During steady operation this load is balanced by the tension of the spring 15S, and the pilot valve 133 is in neutral position as shown in the drawing. If now the speed of the prime mover increases, the oil delivery and in turn the difference of pressure between chambers 145 and 152 increases, causing displacement of the pilot valve toward the right so that pressure oil is discharged from the cylinder 138 into the reservoir 134. Theservornotor piston moves toward the left, tending to decrease the speed of the prime mover. The increase of volume of the cylinder chamber 141 causes an afllux of oil thereto from the air chamber 143 and through the orifice 146 thus causing a temporary drop of pressure in chamber 145. This restrains the excursion of the pilot `valve toward the right and prevents overtravel of the latter, as it has already been disclosed in connection with Figure l, so as to eliminate hunting. Conversely, when the prime mover decelerates the difference of oil pressure between chambers and 152 drops below the tension of spring 158, causes displacement of the pilot valve toward the left and consequent movement of the servomotor piston 140 toward the right tending to increase the prime mover speed. Part of the oil so displaced from chamber 141 flows into chamber 143 against -increasing pressure of the air therein, and part is forced through the restricted orifice 146. The temporary oil pressure increase in chamber 145 restrains the excursion of the pilot valve toward the left and prevents overcorrection on the part of the servomotor. As the speed gradually returns to normal, owing to the leak valve 146 the pressure in chambers 145, 143 and 141 progressively resumes the same value as in chamber 150.

The speed at which the governor maintains the prime mover is dependentV upon the effective area of the orifice 153. Inward or outward movement of the needle valve 154 obtained by adjusting the speed control lever 155 4causes decrease or increase of said area and determines decrease or increase of said speed, respectively. Unlike the governors provided with centrifugal yballs the governor 120 has the same regulating energy at all speeds.

When the governor is employed for the speed regulation of a prime mover used for the propulsion of a vehicle such for example as a locomotive or other railroad or highway vehicle, a device responsive to angular acceleration as diagrammatically shown in smaller scale at 162 may be employed for the anticipatory actuation of the pilot valve thereof. A cylinder 163 secured to the prime mover -or other fixed part of the vehicle has slidably mounted therein a piston 164 connected by a rod 165 with al lever`166 pivoted on the axis 168 and carrying at its *ends weights 170 whose distance from the axis 168 may be Aadjusted by means of their threaded connection vwith lever 166. The center of gravity tem including lever, piston and connecting rod is located at the center of the pivot 168. 'Ihis system is thus in indifferent equilibrium and the angular adjustment thereof relative to the cylinder 163 does not vary upon any translational acceleration of the vehicle. The cylinder chamber171 above piston 164 is connected by way of a conduit 172 provided with a dampening orifice adjustable by means of a needle valve 173 with the servomotor cylinder 141. Springs 174 may be provided tending to hold the oscillating lever in preselected position. It is assumed that the vehicle equipped with the regulator 162 proceeds in the direction of arrow V. As long as it advances on constant grade the piston 164 remains stationary but as soon as a steeper upward grade is encountered and both the Vehicle and the cylinder 163 undergo a slight counterclockwise rotation about an axis parallel tothelpivot 168 the inertia of the oscillating system 166 causes a downward movement of piston 164 relative to the cylinder 163 and oil is sucked from chamber 141. The oil pressure in chamber 145 drops, the pilot valve moves toward the left so as to initiate a displacement of the servomotor piston 140 toward the right tending to increase the speed of the prime mover in advance of the time at which deceleration otherwise resulting would be detected by the governor. The temporary deceleration of the vehicle is thus substantially reduced. Conversely, when a downward directed grade variation is encountered, a slight clockwise rotation of the cylinder 163 occurs, the piston 164 moves inward relatively to the cylinder forcing oil into chamber 141, and displacing the pilot valve 133 toward the right so as to initiate a movement of the servomotor in a direction to decrease the speed of the prime mover.

'It wil-l be readily understood that the angular acceleration responsive device 162 may also be used in connection with centrifugally actuated governors such as 6 and 6. lIt may be further employed in aircraft installations in substitution for the anemometer 104 to actuate the governor pilot valve so as to initiate a propeller pitch increasing or decreasing movement of the servomotor as soon as the aircraft initiates a dive ora climb, respectively. In these aircraft applications gyroscopic means maybe advantageously substituted for the comparatively heavy and bulky oscillating lever 166, as will appear obvious -to those skilled in the art.

While the hydraulic .medium used in the various governors disclosed has been referred to as lubricating oil, any other appropriate fluid may be used in substitution therefor. In the above disclosed speed regulating systems a decrease 'of pressure of the fluid actuating the servomotor thereof causes a reduction of speed of the prime mover. This may be considered a safety feature, for an accidental interruption in the supply of the actuating pressure fluid to the servomotor, as may be vdue to failure of the fluid pump [or rupture of a fluid conduit causes the prime mover to stop.

Various specific examples of embodiments of the inof the oscillating sys.-

vention have been disclosed including devices for actui ating the governor in response to changes of certain operative conditi-ons upon which the speed to be regulated is dependent, namely the electric load on the driven generator, the aircraft air speed, the engine manifold pressure, the grade negotiated by a vehicle; but it is to be definitely understood that according `to `the invention other devices Vmay be employed in operative connection with the governor for actuating the latter in response to-Jor with variations of--one or more preselected operative conditions upon which Ithe speed to be regulated is dependent. And while `the above disclosed embodiments show the application of stabilizing or compensating means to speed regulating systems or governors, according to the invention said stabilizing or compensating means may also be used in connection with any suitable system for regulating one -or more conditions other than speed. It

is thereforefto be expressly understood that the invention is not limited to the specific embodiments shown, but may be used in various -other ways, and various modifications may be made to suit different requirements, and that other changes', substitutions, .additions and omissions may `be made in the construction, arrangement and manner of operation` and adjustment within the limits or scope of the invention as defined in the following claims. And where claims are directed to less than all the elements ofthe complete system disclosed, they ar-e intended to cover possible uses of therecited Velements in installations which may not include the non-recited elements. i

Certain features claimed herein are disclosed in lmy Patents No. 2,364,817, issued December 12, 1944, and No. 2,384,340, issued September 4, 1945.

ll claim:

l. A prime -mover governor including a hydraulic servomotor cylinder, power pist-on means in said cylinder, a plunger valve controlling said piston means, means for shifting said `valve with prime mover speed variations, movable wall means, prime mover load responsive means :operatively .connected with said wall means and adapted to` actuate said wall means even when said plunger valve and piston means are lboth stationary, fluid containing means defined in part by 4one end `of said valve, bysaid piston means `and by said wall means, and a constantly open fluid leak valve providing the only effective fluid passage in or out of said -fluid containingmeans.

2. In a prime mover governor having -a hydraulic servomot-or, piston means in said servomotor, a plunger valve controlling said piston means, flyballs connected to one end of said valve, movable wall means, prime mover load responsive means operatively connected with said wall means to actuate said wall means independently of the movements of said piston means and plunger valve, variable volume 4fluid containing space enclosed -by the opposite end -of -said valve and `by s-aid piston means and wall means, and fluid flow restricting means providing the Ionly effective fluid passage in or out of said enclosed space whereby :changes Iof volume of said space determine temporary pressure variations therein.

3. A prime mover governor including a servomotor cylinder, piston means in said cylinder, 'a plunger valve contro-lling said piston means, means for shifting said valve with prime mover speed Variations, movable wall means, fluid containing means defined in part `by one end 0f 'said valve and by said piston and wall means, the effective fluid-displacing area and stroke 'of said piston means being considerably larger than those of said plunger valve, respectively; a constantly open fluid leak valve providing the only effective fluid passage in or out of said fluid containing means, and -additional means operatively connected with said wall means to actuate the same -with `changes of prime mover load even while said plunger valve :and piston means are stationary to exert anticipatory pressure on said plunger valve.

4. The governorv of claim 1 in which the means for shifting the plunger valve include a pump driven from the prime mover, a fluid conduit connected with the pump, and a flow-restricting orifice in the conduit for applying a fluid differential pressure to the plunger valve.

5. The governor of claim 1 in which the means for shifting the plunger valve include a pump driven from the prime mover, a fluid conduit connected with the pump, an adjustable flow-restricting orifice in the conduit for applying a fluid differential pressure to the plunger valve,

' and orifice adjusting means to vary the governed speed.

6. The governor of claim 3 in which the means for shifting the plunger valve include a fluid pump driven from the prime mover to create a differential fluid pressurey varying with the prime mover speed, and passages through which the plunger valve is subjected to the differential pressure.

7. A hydraulic engine speed regulator, including a con trol valve actuated upon changes of engine speed; a pistom whose adjustment varies with changes of engine fuel supply: a movable wall; additional means to actuate said wall upon variations of a speed-aiecting operative condition even in the absence of any motion of said valve and piston; a variable-volume uid containing space defined in part by said piston, Wall and valve to exert variable operative pressure on said valve; and a iiuid flow restricting orice providing the only effective liuid passage in or out of said space and connecting said space to a uid reservoir at substantially constant pressure.

8. In a'powerplant control apparatus having a servomechanism, a reciprocable member for controlling the servomechanism, housing means providing a iirst chamber an'd a second chamber, said member having a iirst surface subject in one direction to the pressure in the irst chamber and a 'second surface subject in the opposite direction to the pressure in the second chamber, restricted oriiice means connecting said first and second chambers for normally maintaining the same pressure in the two chambers, movable Wall means having an eiective area several times larger than the areas of said lirst and second surfaces and defining in part said first chamber, means responsive to a speed condition of the powerplant for actuating said reciprocable control member, and means responsive to another operating condition of the powerplant for actuating said Wall means.

9. In a regulating apparatus for a Powerplant, the combination of control means for regulating the supply of energy to the powei'plant, a reversible kmotor for actuating -said control means, a movable control member for controlling said motor, said control member having a surface subject to variable iiuid pressure, means for actuating said control member in response to a speed condition of the powerplant, means for transiently varying the pres- .sure of said fluid in response to another operating condition of the powerplant, and means for transiently varying the pressure of said iiuid in response to motion of said motor.

References Cited in the file of this patent UNITED STATES PATENTS 1,013,184 Kramer Jan. 2, 1912 1,576,153 Standerwick Mar. 9, 1926 2,020,847 Miteretr' Nov. 12, 1935 2,117,891 Kalin May 17, 1938 2,232,838 Bryant Feb. 25, 1941 2,235,112 Pulaski Mar. 18, 1941 2,273,407 Lilja Feb. 17, 1942 2,299,824 Kalin Oct. 27, 1942 2,303,752 Meredith Dec. 1, 1942 2,324,516 Kalin July 20, 1943 2,333,184 Kalin Nov. 2, 1943 2,381,160 Hanna Aug. 7, 1945 .FOREIGN PATENTS 160,847 Switzerland June 16, 1933 

